This is an application for continuation of a training program in Oncology: The Molecular Basis of Cancer. The program faculty are composed of twenty-four preceptors directly involved in cancer biology research, fourteen preceptors in areas related to cancer research and six faculty in support roles, with thirty-eight faculty acting in the role of preceptor for both predoctoral and postdoctoral fellows. The t r a i ning faculty currently supervise 110 graduate students and 124 postdoctoral fellows and form a highly interactive community of mentors in a state-of-the-art research facility. Program strengths are its diversity of experimental systems, technical capabilities-support facilities and a combined approach of molecular, cellular and developmental biology. At the same time, courses, symposia, conferences and research collaborations are used to enrich the clinical related aspects of the training. Trainees visit clinical facilities where cancer treatment occurs and meet clinical fellows, with whom they can exchange ideas on translational research efforts. In addition to the special effort to emphasize cancer as a disease, course work, seminar series, symposia and retreats are all used to provide a broad educational experience in diverse experimental systems: prokaryotes, yeast, worms, fruit flies, Xenopus, cell culture, virology and oncology. The ultimate goal is to train original, creative and productive biomedical scientists who will advance our understanding of cancer, its origin, treatment and elimination in a lifetime of research. The training record of this grant in the past bears out our success in this goal.